As businesses expand into multiple states ("multi-state"), the issue arises of whether the "foreign" states can force your company to register and collect use tax. Your company's presence in the foreign state is referred to as "nexus".
Traveling sales persons, jobbers, repair persons, or independent contractors who perform installation or maintenance in a state where the company is not registered may create nexus in that state.

Nexus

Full Definition

As businesses expand into multiple states ("multi-state"), the issue arises of whether the "foreign" states can force your company to register and collect use tax. Your company's presence in the foreign state is referred to as "nexus".
Traveling sales persons, jobbers, repair persons, or independent contractors who perform installation or maintenance in a state where the company is not registered may create nexus in that state.